Rockets and spacecraft are complicated and expensive vehicles with many components. Typically, each engine and each propulsion subsystem in the vehicle has its own control system. When a main flight computer for the rocket or spacecraft wants to issue a command to, for example, create thrust, the main flight computer issues a command to a control system for each engine and propulsion subsystem. Accordingly, every time a component on the rocket or spacecraft is modified, added or removed, the entire main flight computer system has to be updated to take into account the changes.